escaping-url.md 1.3 KB
Escaping URLs
This method is basically an alias for PHP's rawurlencode() which has applied
RFC 3986 since PHP 5.3. It is included primarily for consistency.
URL escaping applies to data being inserted into a URL and not to the whole URL itself.
Example of Bad URL Escaping
XSS attacks are easy if data inserted into URLs is not escaped properly:
<?php header('Content-Type: application/xhtml+xml; charset=UTF-8'); ?>
<!DOCTYPE html>
<?php
$input = <<<INPUT
" onmouseover="alert('zf2')
INPUT;
?>
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<title>Unescaped URL data</title>
<meta charset="UTF-8"/>
</head>
<body>
<a href="http://example.com/?name=<?= $input ?>">Click here!</a>
</body>
</html>
Example of Good URL Escaping
By properly escaping data in URLs by using escapeUrl(), we can prevent XSS
attacks:
<?php header('Content-Type: application/xhtml+xml; charset=UTF-8'); ?>
<!DOCTYPE html>
<?php
$input = <<<INPUT
" onmouseover="alert('zf2')
INPUT;
$escaper = new Zend\Escaper\Escaper('utf-8');
$output = $escaper->escapeUrl($input);
?>
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<title>Unescaped URL data</title>
<meta charset="UTF-8"/>
</head>
<body>
<a href="http://example.com/?name=<?= $output ?>">Click here!</a>
</body>
</html>